What letter in a 92 Chevy truck vin tells you it has posi rear end?
There is no single letter in a 1992 Chevy truck VIN that definitively indicates it has a Posi-traction (limited-slip) rear differential. The VIN encodes major vehicle specifications, but finer details like the type of rear axle are usually found on the vehicle's data plate (often located on the driver's side doorjamb) or in the owner's manual. You'd need to check those resources, or visually inspect the rear differential itself for markings.